The syntax is <%# Eval(“…”) %> You could do something like <asp:ImageButton Visible=”<%# ShowImg(Eval(Container.DataItem,”Message”)) %>” /> and in your codebehind: boolean ShowImg(string msg) { return (msg == HttpContext.Current.Profile.UserName); }
You need to use single quotes to prevent interpolation happening in your calling shell. $ bash -c ‘echo arg 0: $0, arg 1: $1’ arg1 arg2 arg 0: arg1, arg 1: arg2 Or escape the variables in your double-quoted string. Which to use might depend on exactly what you want to put in your snippet … Read more
Use require to load modules at runtime. It often a good idea to wrap this in a block (not string) eval in case the module can’t be loaded. eval { require My::Module; My::Module->import(); 1; } or do { my $error = $@; # Module load failed. You could recover, try loading # an alternate module, … Read more
You can use sandbox support in nodejs with vm.runInContext(‘js code’, context), sample in api documentation: https://nodejs.org/api/vm.html#vm_vm_runinthiscontext_code_options const util = require(‘util’); const vm = require(‘vm’); const sandbox = { globalVar: 1 }; vm.createContext(sandbox); for (var i = 0; i < 10; ++i) { vm.runInContext(‘globalVar *= 2;’, sandbox); } console.log(util.inspect(sandbox)); // { globalVar: 1024 } WARN: As … Read more
When you use a command substitution (i.e., the $(…) construct), you are creating a subshell. Subshells inherit variables from their parent shells, but this only works one way: A subshell cannot modify the environment of its parent shell. Your variable e is set within a subshell, but not the parent shell. There are two ways to … Read more
eval() takes the string it is given, and runs it as if it were plain JavaScript code. It is considered “evil” because: It over-complicates things – Most cases where eval() is used, there would be a much simpler solution that didn’t require it. This example in the question is a perfect case in point: there … Read more
There’s a shortcut for limited (ie. simple) math expressions by using the DataTable.Compute method. Obviously, this isn’t robust (limited functionality) and feels hackish to misuse the DataTable for this purpose, but I figured I would add to the current answers. Example: var result = new DataTable().Compute(“3+(7/3.5)”, null); // 5 “Sin(90)” wouldn’t work with this approach. … Read more
If the statements you are trying to “eval” always return the same data type, you could write an eval() function that uses the EXECUTE mentioned by Grzegorz. create or replace function eval(expression text) returns integer as $body$ declare result integer; begin execute expression into result; return result; end; $body$ language plpgsql Then you could do … Read more
The only case I know of (other than “I have this string and I want to execute it”) is dynamically dealing with local and global variables. Ruby has methods to get the names of local and global variables, but it lacks methods to get or set their values based on these names. The only way … Read more
json.org has a nice javascript library simple usage: JSON.parse(‘[{“some”:”json”}]’); JSON.stringify([{some:’json’}]); Edit: As pointed out in comments, this uses eval if you look through its source (although it looks to be sanitized first) to avoid it completely, look at json_parse or json-sans-eval json2.js is insecure, json_parse.js is slow, json-sans-eval.js is non-validating